Coix Seed May Affect Human Immune Function

Coix (Coix lacryma-jobi Linné. var. mayuen Stapf) is, unlike many herbs used in Chinese traditional medicines, often used as a single agent. Coix seed has its specific constituents coixenolide and coixol. This review summarizes the effects of coix seed on human pathology and physiology, and the roles of coixenolide and coixol on the effects. The comprehensive literature search was conducted using PubMed, Citation Information by National Institute of Informatics of Japan (CiNii), University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR), and ClinicalTrials.gov databases. Some studies suggest that coix seed promotes the spontaneous regression of viral infections of the skin. Meanwhile, kanglite, a purified oil agent used for cancer therapy, has been implied to increase the ratio of CD4 + T cells in the peripheral blood of cancer patients undergoing treatment. These studies seem to indicate that coix seed may affect cellular immune function. However, there are limitations to the individual studies on which the above consideration is based, and thereby, it is not conclusive what specific immune or clinical indices coix seed affects. In addition, the effects of coixol on human immune function have not been clarified. Therefore, coix seed seems promising for health promotion and presents a challengeable and attractive theme for natural product chemists, pharmacologists, immunologists, and clinicians.